CVE-2009-3621

MEDIUMNVD 5.55.5—
EchelonGraph scoreMEDIUM confidence

Score 5.5 from GitHub Security Advisory published 2022-05-02. NVD baseline CVSS 5.5; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
Weaponized
5.5
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS: 1%CVSS: 5.5Exploit: NoneExposed: 0

A fix is available — apply it.

net/unix/af_unix.c in the Linux kernel 2.6.31.4 and earlier allows local users to cause a denial of service (system hang) by creating an abstract-namespace AF_UNIX listening socket, performing a shutdown operation on this socket, and then performing a series of connect operations to this socket.

CVSS v3
5.5
EG Score
5.5(medium)
EG Risk
—
EPSS
58.7%
KEV
Not listed

Published

October 22, 2009

Last Modified

April 23, 2026

References (52)

Vendor Advisories for CVE-2009-3621(2)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Patch Availability(4)

Vendor / EcosystemFixed in / PatchReleasedSource
ubuntulinux-image-2.6.31-16-powerpc (2.6.31-16.52) @ karmic2026-05-30ubuntu
redhatkernel-0:2.6.9-89.0.18.EL2009-12-15redhat
redhatkernel-0:2.6.18-164.9.1.el52009-12-15redhat
redhatkernel-rt-0:2.6.24.7-137.el5rt2009-11-03redhat

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Additional Vendor Advisories

(2)

Vendors that published advisories for this CVE beyond the curated set above. Broader coverage but minimal per-row detail — click through for the original advisory.

Data Freshness Timeline

(refreshed 7× in last 7d / 36× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-07-22 21:43 UTCEG score recompute
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  52. 2026-05-30 14:51 UTCEG score recompute
  53. 2026-05-30 14:51 UTCVendor advisory
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Publicly available exploits

(1 reference)

Working exploit code is in the public domain (1 Exploit-DB entry). Defenders should treat patch urgency accordingly — public PoCs typically lead to mass-exploitation within 24-72 hours.

  • Exploit-DBEDB-10022✓ verified
    First seen Nov 10, 2009

    Linux Kernel 2.6.31.4 - 'unix_stream_connect()' Local Denial of Service

    Open source ↗

Related CVEs(same vendor + same CWE)

Frequently asked(5)

What is CVE-2009-3621?
CVE-2009-3621 is a medium vulnerability published on October 22, 2009. net/unix/afunix.c in the Linux kernel 2.6.31.4 and earlier allows local users to cause a denial of service (system hang) by creating an abstract-namespace AFUNIX listening socket, performing a shutdown operation on this socket, and then performing a series of connect operations to this socket.
When was CVE-2009-3621 disclosed?
CVE-2009-3621 was first published in the National Vulnerability Database on October 22, 2009, with the most recent update on April 23, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2009-3621 actively exploited?
CVE-2009-3621 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 58.7% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2009-3621?
CVE-2009-3621 has a CVSS v3 base score of 5.5 (NVD).
How do I remediate CVE-2009-3621?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2009-3621, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

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